This invention relates generally to powered surgical handpieces that include conduits through which suction is drawn. More particularly, this invention relates to this class of handpiece with a valve that can be set to selectively, accurately, regulate flow through the suction conduit.
Endoscopic surgical procedures are routinely performed in order to accomplish various surgical tasks. In an endoscopic surgical procedure, small incisions, called portals, are formed in the patient. An endoscope, which is a device that allows medical personnel to view the surgical site, is inserted in one of the portals. Surgical instruments used to perform a specific surgical task are inserted into other portals. The surgeon views the surgical site through the endoscope to determine how to manipulate the surgical instruments in order to accomplish the surgical procedure. An advantage of performing endoscopic surgery is that, since the portions of the body that are cut open are minimized, the portions of the body that need to heal after surgery are likewise reduced. Moreover, during an endoscopic surgical procedure, only relatively small portions of the patient""s internal organs and tissue are exposed to the open environment. This minimal opening of the patient""s body lessens the extent to which a patient""s organs and tissue are open to infection.
The ability to perform endoscopic surgery has been enhanced by the development of powered surgical tools especially designed to perform endoscopic surgical procedures. One such tool, for example, is sold by the Applicant""s Assignee under the trademark HUMMER II. This tool is in the form of a cylindrical handpiece designed to be held in the hand of the surgeon. Internal to the handpiece there is a motor. A front end of the handpiece is provided with a coupling assembly for releasably holding a cutting accessory. The types of cutting accessories that are attached to this handpiece include shavers, resectors, planers and burrs. Integral with the motor and coupling assembly is a means for transmitting the rotary power developed by the motor to the cutting accessory.
The handpiece also has a suction conduit. This is because, in an endoscopic surgical procedure, irrigating fluid is introduced into the surgical site. This fluid serves as a transport media for removing debris from the surgical site. In order to remove the irrigating fluid, and the material in the fluid, a suction path is provided through the cutting accessory and the handpiece. A suction pump is connected to the handpiece and provides the suction force for drawing the fluid and material away from the surgical site. In order to control the suction flow through the cutting accessory and the handpiece, the handpiece is provided with a manually operated valve. Thus, with a single handpiece, a surgeon both manipulates the cutting accessory and controls the suction of material away from the surgical site.
For the above reasons, presently available handpieces have proven to be very useful tools for performing surgical procedures. Nevertheless, there is a limitation associated with the suction systems that are integral with these handpieces. Specifically it is very difficult for a surgeon to regulate the suction rate, the rate at which fluid and debris are drawn away from the surgical site through the handpiece. Presently available handpieces have valves that allow variable control of suction flow through the associated suction conduit. However, it is difficult to precisely set the currently available valves to specific flow rate settings between their fully closed and fully opened positions.
In order to regulate suction through the handpiece conduit, some surgeons rely on an assistant to regulate the operation of the suction pump to which the conduit is attached. In this process, the on-handpiece suction valve is simply placed in the full open state. The surgeon voices commands to the assistant indicating the amount of suction that is desired during various stages of the surgical procedure. Based on these commands, the assistant regulates the setting of the suction pump to regulate the suction drawn from the surgical site. One disadvantage of this system is that the surgeon must verbalize his/her commands. When providing these commands, the surgeon must speak loud enough so that the assistant can hear them over the presence of ambient noise in the operating room. Requiring a surgeon to take this action can detract the surgeon""s attention from the surgical site. Moreover, in this control system, in addition to the surgeon speaking the commands, the assistant must hear the commands, mentally process the commands and then manipulate the appropriate control switches to cause the desired changes in suction level. The processing of all these steps means that there can be a significant delay between when the surgeon first decides that the suction flow should be adjusted and the desired adjustment occurs.
One solution that has been suggested to this problem is to provide index marks on the body of the handpiece adjacent the switch member of the valve. The surgeon can then set the valve to a desired position by positioning the switch member relative to the index marks. A disadvantage of this arrangement is that it requires the surgeon to focus his/her eyes on the position of the valve switch member. In order to take this action, the surgeon has to divert his/her eyes and attention from the surgical site. Clearly, it is more desirable for the surgeon""s eyes to remain focused on the surgical site and the procedure being performed at the site.
This invention relates to a new powered surgical handpiece with a suction conduit and a valve that facilitates the accurate control of fluid flow through the suction conduit. The valve of this invention includes an indexing assembly. The indexing assembly provides tactile feedback to the person actuating the valve regarding the position of the valve. Thus, an individual, based on feel alone, can set the valve to at least one known intermediate flow rate state between the full off and full on states.